mpi_pack_external_size(3openmpi) [osx man page]

MPI_Pack_external_size(3OpenMPI)										  MPI_Pack_external_size(3OpenMPI)

NAME

       MPI_Pack_external_size - Calculates upper bound on space needed to write to a portable format

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Pack_external_size(char *datarep, int incount,
	    MPI_Datatype datatype, MPI_Aint *size)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_PACK_EXTERNAL_SIZE(DATAREP, INCOUNT, DATATYPE, SIZE, IERROR)

	    INTEGER	   INCOUNT, DATATYPE, IERROR
	    INTEGER (KIND=MPI_ADDRESS_KIND) SIZE
	    CHARACTER*(*)  DATAREP

C++ Syntax
       #include <mpi.h>
       MPI::Aint MPI::Datatype::Pack_external_size(const char* datarep,
	    int incount) const

INPUT PARAMETERS

       datarep	 Data representation (string).

       incount	 Number of input data items (integer).

       datatype  Datatype of each input data item (handle).

OUTPUT PARAMETERS

       size	 Upper bound on size of packed message, in bytes (integer).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_Pack_external_size  allows the application to find out how much space is needed to pack a message in the portable format defined by the
       MPI Forum. It returns in size an upper bound on the increment in position that would occur in a call to	MPI_Pack_external  with  the  same
       values for datarep, incount, and datatype.

       The  call returns an upper bound, rather than an exact bound, as the exact amount of space needed to pack the message may depend on context
       and alignment (e.g., the first message packed in a packing unit may take more space).

NOTES

       The datarep argument specifies the data format. The only valid value in the current version of MPI is "external32". The	argument  is  pro-
       vided for future extensibility.

ERRORS

       Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ func-
       tions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception  mechanism
       will be used to throw an MPI:Exception object.

       Before  the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for
       I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN  may	be
       used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

       See the MPI man page for a full list of MPI error codes.

SEE ALSO

       MPI_Pack_external
       MPI_Unpack_external

Open MPI 1.2							  September 2006				  MPI_Pack_external_size(3OpenMPI)

MPI_Type_get_true_extent(3OpenMPI)										MPI_Type_get_true_extent(3OpenMPI)

NAME

       MPI_Type_get_true_extent - Returns the true lower bound and extent of a data type's corresponding typemap, ignoring MPI_UB and MPI_LB mark-
       ers.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Type_get_true_extent(MPI_Datatype datatype,
	    MPI_Aint *true_lb, MPI_Aint *true_extent)

Fortran Syntax (see FORTRAN 77 NOTES)
       INCLUDE 'mpif.h'
       MPI_TYPE_GET_TRUE_EXTENT(DATATYPE, TRUE_LB, TRUE_EXTENT, IERROR)
	    INTEGER   DATATYPE, IERROR
	    INTEGER(KIND=MPI_ADDRESS_KIND) TRUE_LB, TRUE_EXTENT

C++ Syntax
       #include <mpi.h>
       void MPI::Datatype::Get_true_extent(MPI::Aint& true_lb,
	    MPI::Aint& true_extent) const

INPUT PARAMETER

       datatype  Data type for which information is wanted (handle).

OUTPUT PARAMETERS

       true_lb	 True lower bound of data type (integer).

       true_extent
		 True size of data type (integer).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       The true_lb parameter returns the offset of the lowest unit of store that is addressed by the data type, that is, the lower  bound  of  the
       corresponding  typemap,	ignoring  MPI_LB markers. The true_extent parameter returns the true size of the data type, that is, the extent of
       the corresponding typemap, ignoring MPI_LB and MPI_UB markers, and performing no rounding for alignment.

       The true_extent is the minimum number of bytes of memory necessary to hold a data type, uncompressed.

       See Section 4.14.3 of the MPI-2 standard for more detailed definitions of these parameters in relation to the typemap.

FORTRAN 77 NOTES
       The MPI standard prescribes portable Fortran syntax for the TRUE_LB and TRUE_EXTENT arguments only for Fortran 90. FORTRAN 77 users may use
       the non-portable syntax

	    INTEGER*MPI_ADDRESS_KIND TRUE_LB
       or
	    INTEGER*MPI_ADDRESS_KIND TRUE_EXTENT

       where MPI_ADDRESS_KIND is a constant defined in mpif.h and gives the length of the declared integer in bytes.

ERRORS

       Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ func-
       tions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception  mechanism
       will be used to throw an MPI:Exception object.

       Before  the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for
       I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN  may	be
       used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

Open MPI 1.2							  September 2006				MPI_Type_get_true_extent(3OpenMPI)